The study is assembling a well-characterized cohort of patients with presumed chronic Lyme disease and relevant controls. These patients are being extensively evaluated in a cross-sectional study and the neuroborreliosis patients will be followed prospectively after therapy with intravenous ceftriaxone. These studies will yield a prospective database upon which stringent diagnostic criteria can be established and future therapeutic trials can be designed.At this point, 58 patients and controls have been enrolled in the study. It is still too early to draw conclusions from the analysis of the results of the multiple and extensive testing done in the enrolled patients. Multiple research projects are being developed based on the findings in this population. All of these projects are ongoing. In collaboration with Dr. Stephen Fischer from the Clinical Pathology Department at the Warren Grant Magnuson Clinical Center, a new PCR assay for Borrelia has been developed and is now been clinically applied at the Clinical Center. The PCR is also being used to seek for the presence of Borrelia in frozen brain biopsies from patients with Alzheimer?s disease and matched controls. This is being performed in collaboration with Dr. Juan Troncoso from JHU, who provided the brain biopsies.In collaboration with Dr. Roland Martin and Dr. Henry McFarland from NINDS, Borrelia-specific T cell clones have been isolated from peripheral blood, joint and/or cerebrospinal fluid from patients with chronic neuroborreliosis and Lyme arthritis. The cytokine profiles of some of these clones have been studied. Also, one clone has been studied using combinatorial peptide libraries for fine definition of the reactive peptide, and multiple peptides have been defined. In collaboration with Dr. Grafman from NINDS, we are studying the neuropsychological findings of patients suffering from chronic Lyme disease and controls.In collaboration with Dr. Lawrence Shotland from NIDCD, we are studying the audiological findings in patients with chronic Lyme disease. In collaboration with Dr. Mario Philipp and his group at Tulane University Medical Center, we are attempting to formulate a simpler diagnostic procedure for Lyme borreliosis. The test we are developing is simple to perform (ELISA format) and appears to be also sensitive and specific. The ELISA uses a small synthetic peptide whose sequence was derived from a lipoprotein of Borrelia burgdorferi. - Lyme disease, chronic disease, immunopathology, infection, Borrelia burgdorferi, neurologic disease, arthritis - Human Subjects